Internal lock pin for scarifier teeth



Sept. 7, 1954 v E. SMALL 2,688,475

INTERNAL LOCK PIN FOR SCARIF'IER TEETH Filed 001,- 24, 1949 IN VEN TOR. 51 5257? 775/1444 1.

I477'OE/VEYS.

Patented Sept. 7, 1954 UNITED STATES PATENT OFFICE INTERNAL LOCK PIN FOR SCARIFIER TEETH 1 Claim.

This invention relates to an internal pin lock for locking two parts together in assembled and telescoping relationship. It is particularly adaptable for use in mounting shoes on scarifier teeth in earth working equipment but may be used wherever two parts are telescoped together and wherein it is desired to lock the parts against separation or againstsliding movement of one part relatively to the other.

In earth working equipment it has been customary heretofore to provide a shoe that is detachably mounted on a foot on the bottom of each scarifier tooth. The shoe is ordinarily formed of relatively hard abrasion-resisting metal or may be hard faced with a hard facing alloy deposited thereon as by welding. Despite such abrasionresisting precautions it is necessary to remove and replace the shoes from time to time. These shoes have heretofore been attached to the foot of the scarifier tooth by means of nuts and bolts which extend through registrable apertures formed in both parts. When nuts and bolts are employed the head of the bolt and the nut are exposed on the sides of the shoe and, being thus unprotected, become severely worn or abraded so that the bolt invariably must be replaced whenever the shoe is replaced.

It is an object of the present invention to provide a pin lock for locking the shoe and the scarifier tooth in assembled relationship and which is so designed that the pin will be efiectively retained in place or in looking relationship in such a manner as to be adequately protected. At the same time it is possible to readily remove the pin whenever it is desired to replace a shoe on the scarifier tooth with a new or repaired shoe.

Another object of the invention is to provide a pin lock wherein the pin can be easily installed or removed as desired and wherein the pin as well as its retaining means are disposed well within the outline of the shoe or outer member so that it will be effectively protected against wear or abrasion.

With the foregoing and other objects in view, which will be made manifest in the following detailed description and specifically pointed out in the appended claim, reference is had to the accompanying drawings for an illustrative embodiment of the invention, wherein:

Figure 1 is an exploded view of the lower end of a scarifier tooth, its detachable shoe, and the parts of the pin lock embodying the present invention;

Fig. 2 is a transverse section through the shoe;

Fig. 3 is a transverse section through the shoe,

2 the foot of the scarifier tooth, and illustrating the pin lock embodying the present invention in applied or looking position thereon;

Fig. 4 is a transverse section through an alternative form of construction embodying the present invention; and

Fig. 5 is a transverse section illustrating the pin lock applied to the form of construction illustrated in Fig. 4.

Referring to the accompanying drawings wherein similar reference characters designate similar parts throughout, it will be appreciated that the improved pin lock can be employed Wherever two parts are telescopically arranged or assembled but as the present invention has been primarily designed to be used in looking a scarifier shoe onto its tooth it will be described in connection therewith. In the drawing, ll) indicates a scarifier tooth having a forwardly extending tapered foot I I at its bottom designed to be receivable in a recess l2 in a scarifier shoe generally indicated at l3. In the form shown in Figs. 1 to 3, inclusive, the scarifier shoe consists of for wardly convergent top and bottom walls [4 and I5 connected by side walls I 6 and H. Registrable apertures are formed in the foot I I and inthe side walls It and ill, the aperture in the foot being indicated at it and the apertures in the side walls being indicated at 19 and 20. As will be observed from Figs. 2 and 3, the aperture l9 in the side wall I! is somewhat smaller in diameter than the apertures l8 and 28 so that the inner face of the side wall I! forms a substantial shoulder around the aperture l9 adapted to be engaged by a shoulder 2| on the locking-pin 22. The locking pin decreases in diameter from one end to the other so that there is a small end 23 that is receivable in the small aperture 19. The mutually engageable shoulders serve to limit sliding movement of the pin 22 in one direction through the registered apertures l8, l9 and 20 and while the use of opposed shoulders on the pin and side wall IT is preferred the use of a tapered pin as well as tapering registrable apertures can be employed if desired and the same result of limiting movement of the pin through the apertures can be secured.

On the outer face of the side wall It a small recess 24 is formed surrounding the aperture 20 and a malleable metal washer 25 having an aperture 26 therethrough is welded, such as by weld 21, in this recess. Any other means for rigidly securing this washer in the recess can be employed if desired. The aperture 26 in the washer is at least as large as the aperture 20 in its initial condition as illustrated in Fig. 2 so that the large end of the pin 22 may be readily slipped there through. When the pin has been passed through the aperture 26 in the washer and is seated in the registering apertures l8, l9 and 20, the washer is deformed or bent into a flat condition partially overlying the large end of the pin as shown in Fig. 3. As the pin is limited in its sliding movement in one direction by the engaging shoulders, or by mutually engaging tapers if these are employed, and is retained against movement in the other direction by the overlying deformed washer 25, the pin will serve to adequately lock the two parts together in telescoping or assembled relationship. It will be observed in this form of construction that the small end of the pin 23 does not project outwardly beyond the side l7- so as to j be subject to abrasion. Likewise, the large end of the pin does not project outwardly beyondthe outer side of the side 16. Furthermore, as the washer 25 is disposed within the recess 24 the entire pin lock is disposed within the outer boundary or overall contour of the shoe. quently, even though the shoe may be subject to extreme abrasive wear, neither the washer nor the pin will be so subjected. When it is desired to remove and replace a shoe it is merely necessary to apply a punch or similar implement to the exposed small end of the pinand drive the pin reversely through the registering apertures. In so doing the pin merely deforms the malleable washer, returning it to substantially the same condition illustrated in Fig. 2. A removed shoe may either be junked as having been too severely worn, or it may be repaired and hard faced and re-applied to the scarifier tooth. In re-applying it the pin is re-installed through the swasher and the washer deformed or returned to the position shown in Fig. 3. V

In the form illustrated in Figs. 4 and 5, the shoe consists merely of a top bar 30 adapted to overlie the foot I I on the scarifier tooth. To the under side of this top bar there may be welded or otherwise secured a U-shaped strap 3| in one side of which a relatively small aperture 32 is formed corresponding to the small aperture 19. In the other side of the strap there is formed a registrable aperture 33 the edges of which are bent outwardly as indicated at 34. These edges are somewhat malleable as the strap is formed of relatively soft or mild steel which is comparative- 1y malleable. The aperture 33, when in its expanded position shown in Fig. 4, is of such a size as to receive the maximum diameter of the pin therethrough. The shoulder 35 adjacent one end of the pin is engageable with the opposite side of the strap around aperture 32 to limit the inserting movement of the pin. When the pin is in applied position the deformed metal at 34 is pounded or bent into the position shown in Fig. overlying the shoulder 36 and assuming a position substantially flush with the side in which the aperture 33 is formed. This metal may also be caused to assume a position substantially flush with the end of the pin so as to avoid any pro- Consetuberances that would be subject to wear or abrasion. In this position, as shown in Fig. 5, the pin is retained in its innermost or locking position. When it is desired to remove or replace the shoe the pin may be pounded out of the registering apertures, as previously described, returning the edges 34 of the aperture 33 to the position shown in Fig. 4. On repairing the shoe it may again be applied to the scarifier tooth as previously explained, or a substitute shoe may be applied and the pin re-installed.

It will be appreciated from the above described constructions that the pin when installed is effectively protected so that it will not be subject to wear and ordinarily does not require replacement. The pin is retained in locking position adequately at all times and yet when it is desired to remove the pin this can be easily accomplished. In both constructions the locking or retaining means that retains the pin in position is disposed within the overall contour of the outer member. This type of lock may be advantageously employed to hold two parts in telescopic relationship wherever these parts are required to slide or closely fit within a third part. The. pin and its lock do not interfere with the outer of the two parts telescoping into a third part even though there may be a very close fit within the third part.

Various changes may be made in the details of the construction without departing from the spirit and scope of the invention as defined by the appended claim.

I claim:

A pin lock for locking together two members 1 comprising a scarifier shoe, a scarifier tooth, said tooth being in telescoping relationship with the shoe, registrable apertures formed in both the scarifier shoe and the scarifier tooth, a pin receivable. therein, the pin decreasing in diameter from one end to the other and the apertures being shaped complementary to the. pin so that movement of the pin through the apertures will be limited in one direction, the scarifier shoe having a recess in its outer side, and a deformable lock washer secured in. said recess having an aperture therethrough through which the pin is receivable and being adapted to be deformed into a position lying wholly within the recess and partially overlying the large end of the pin to retain the pin in its innermost position in the apertures.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 933,634 Dougherty et al Sept. 7, 1909 1,114,239 Downing Oct. 20, 1914 1,280,302 Richardson Oct. 1, 1918 1,388,657 MacDonald et a1. Aug. 23, 1921 1,531,848 Davis et al. Mar. 31, 1925 1,817,720 Townsend Aug. 4, 1931 2,222,071 Gustafson Nov. 19, 1940 2,242,793 Philbrick May 20, 1941 2,365,228 Vanderzee Dec. 19, 1944 2,426,174 Bottomley Aug. 26, 1947 

